(I) Upstream Channel Limitations
Some prior art methods and systems allow for providing interactivity between an end-user, such as a video information user equipped with a set-top-box, and video providers or other service providers over networks, such as broadband networks.
The interaction between the end-user and the service provider involves sending various signals, such as media signals, control and status signals from an end-user (upstream) to the service provider and to the end-user (downstream). The upstream capacity is much more limited than the downstream capacity.
There is a need to provide a system and method for providing interactivity that reduces the amount of signals sent via upstream channels.
Many systems and methods for providing interactivity are based upon the TCP/IP suit of communication protocols or other communication protocols that provide reliability. The TCP/IP suit of protocols includes a transport layer that provides for reliability and integrity of a communication link. The reliability and integrity are achieved by exchanging messages, such as acknowledge messages and the like, both downstream and upstream. Accordingly, the use of TCP/IP suite of protocols or other communication protocols that require the exchange of messages further limits the availability of upstream channels.
There is a need to provide a system and method for providing interactivity that affords relatively reliable provision of downstream signals, without loading the upstream channels.
(II) Providing On-Screen Menus to a Large Number of Set-Top-Boxes.
The provision of on screen menus and allowing an end-user to interact has various advantages. First, the provision of menus eases the interaction between an end-user and a service provider. Second, the provision of menus can reduce the computational load on the set-top-box that usually has limited processing resources. U.S Pat. No. 6,055,560 of Mills et al. describes a very complex system and method to provide interactivity for a networked video server. The system has a packet switched network for switching control signals, a video switched network for allowing to provide video programs, and at least two level gateways for establishing sessions and for interchanging signals between the packet switched network and the video switched network. The system has a plurality of application engines, a plurality of application tables, a shared queue, a multitasking operating system, set-top-box application tables and an application server code for allowing to interact with set-top-boxes. Each application table tracks a status of a single set-top-box in implementing the application. The application engines take turns in accessing the shared queue to retrieve event reports that are forwarded by the set-top-boxes. Each application involves displaying a panel (visual content) on a television set and reacting to events, such as a reception of inputs provided by a viewer of the television set. An execution of an application requires the set-top-box to provide relatively many upstream signals. The signals are stored in the shared queue. Each time a user turns on a set-top-box to initiate some kind of interaction with the system and each time the television is turned on a video dial tone is provided by the set-top-box over a video dial tone network.
The system described in U.S. Pat. No. 6,055,560 has some disadvantages. First, it requires exchanging relatively many signals with each set-top-box. As the available bandwidth of the upstream channels is very limited, the system is not suited to handle a very large number of set-top-boxes. Second, tracking the status of a very large number of set-top-boxes and managing multiple application engines in view of the status of a large number of set-top-boxes is very complicated, very costly and is not effective. The system and method are uni-cast oriented and not broadcast oriented. Third, as each set-top-box is connected to two distinct networks (video switched network and packet switched network) over two distinct connections, for receiving data and video signals, each set-top-box needs to have two tuners, one for receiving video and the other for receiving data. Accordingly, the system and method described in U.S. Pat. No. 6,055,560 are not adjusted to operate in conjunction with set-top-boxes that have a single tuner.
There is a need to provide a system and method for allowing interactivity between set-top-boxes and a service provider that is adapted to handle a very large number of set-top-boxes. There is a need to provide an efficient, and cost effective system and method for allowing interactivity between set-top-boxes and a service provider. There is a need to implement a method that does not require a constant tracking of a set-top-boxes status in implementing an application. There is a need to implement a method that simplifies the process of presenting predefined images upon a display unit coupled to a set-top-box. There is a need to provide a system and method that reduces the load on the processing and memory resources of the set-top-box.
(III) Single Tuner Set-Top-Box Limitations
Broadband communication systems are known in the art. The main types include video oriented communication systems and data oriented communication systems. Video oriented communication systems were originally designed for television broadcast transmissions and today include modifications, which enable narrowcast transmissions as well as data communications there through. Data oriented communication systems are used for a plurality of data and multimedia application packets. Conventionally, downstream channels (from the cable service operator to the end-user) are used to carry either only IP packets or only native MPEG programs over MPEG transport. This requires the cable operator to perform fixed allocation of downstream resources for different services, which limits the resource usage efficiency, especially for the downstream bandwidth.
Cable Modem Termination Systems (CMTS) are known in the art. Such systems are installed in a cable head-end and are connected to a plurality (conventionally thousands) of Cable Modems (CM) via a Hybrid Fiber/Coaxial (HFC) Network. A conventional single CMTS board transmits downstream information on a single channel and receives upstream information from one or more (usually not more than 8) upstream channels. Upstream channels that are connected to a single CMTS board can be received from many nodes (usually for areas which are characterized by a small number of cable modem users) or from a single node (usually for areas which are characterized by a large number of cable modem users).
The operation of a conventional CMTS is generally predefined, where the cable modem users are configured to utilize a specific CMTS downstream channel. Each CMTS downstream channel has specific associated upstream channels. The CMTS board uses its associated downstream channel, to provide upstream channels and time slot information to the CMs on which they can transmit information back to the head-end, at any given time.
An article, “Multimedia Traffic Engineering for HFC Networks” by John T. Chapman from Cisco Systems (Nov. 29, 1999), discusses possible CMTS architectures contingent on penetration of CMs and broadband services.
Digital video and other media are typically transmitted in a compressed form, encapsulated in MPEG transport packets, which include information associating them to a specific stream. In general, digital transmission dramatically increases the potential network capacity. Ten to twenty digital video channels can be transmitted using a communication channel. Digital transmission further provides data transmission, and MPEG transport.
New generations of set-top-boxes (STB's) includes two downstream tuners, one for video, one for data (e.g., these STB's are equipped with a cable modem). The ability to transmit video and data combined together leads to a new class of applications, which are classified under Interactive TV (or sometime referred too as Enhanced TV). For set-top devices that have two different paths one for video and one for data, interactive applications that are very trivial to implement, although the implementations can be limited by upstream constraints, as mentioned in section (i).
There is a need to provide a method and system for allowing interactivity between single tuner set-top-boxes and a service provider.